Protractor



April 5, 1938. L. w WOLF 2,113,524

PROTRACTOR Filed May 21, 1935 Il III Milli INVENTOR BY W' i mgvxfzw A l@fwf@ ATTORNEY Patented Apr. 5, 1938 UNITED STATES PATENT OFFICEPROTRACTOR Lem W. Wolfe, Maracaibo, Venezuela Application May 21, 1935,.Sera1-.N0.x22,615,

2 Claims.

The. inventionsI relates z to; a protractor.

The primary object: of the-` invention is the provision. ofV anYinstrument of'l this character wherein through. the-use; of azheadaspirit level body, a; protractonscale anda rulingblade. thesebeing'adjustably related; there can be determined accurately-therequired set of a piece of work or several lays of work, particularly inthe placement of angle joinders.l between pipe sections or runs thereofwhere suchpipe sections or runs are disposed out of alignment either inthe same planewith each other or oneat a higher level than the other sothat the artiflcer will be able to make the required cut without wasteof material. and without mental labor and time' required as would-beordinarily spentthrough the service of other instrumentalities;

A still further object of the invention is the provision of aninstrument of. this character, wherein the construction thereof is novelin form and the degree scales and spirit levels are disposedthereinsothat readings of the same may be had at a glance and the-adjustableparts are susceptible of being latched to hold the-same in determinedpositions so that accuracy will be assured thereby.

A still further object of the invention is the provision of aninstrument of this character, which is comparatively simple in itsconstruction, thoroughly reliable and eilicient in its operation,strong, durable, readily and easily manipulated and adjusted andinexpensive to manufacture.

With these and other objects in view, the ino vention consists in thefeatures of construction,

combination and arrangement of parts as will be hereinafter more fullydescribed, illustrated in the accompanying drawing, which discloses thepreferred embodiment of the invention and pointed out in the claimshereunto appended.

In the accompanying drawing:

Figure 1 is a plan view of the instrument constructed in accordance withthe invention.

Figure 2 is a similar view looking toward the lopposite side thereof andpartly broken away.

Figure 3 is a sectional view taken on the line 3-3 of Figure 2 lookingin the direction of the arrows.

Figure 4 is an end elevation.

Figure 5 is a fragmentary sectional view taken on the line 5-5 of Figurel looking in the direction of the arrows.

Figure 6 is a fragmentary sectional View showing in detail the thumbscrew lock for the sliding blade or beam of the instrument.

Figure'l is a; detailedzplanA view of the adjustinggearings for theprotractor-scale ring;r

Similar reference characters indicateV corresponding parts throughoutAthe several views in the drawing.

Referring tothe drawing in detail, particularly Figures 1 to '7inclusive, the instrument comprises a main frame Ill. which constitutesa body or stock having at. one end thereof a straight edge II-whichiscut into to provide a V-shaped notch I2 forming a centering head whileat one sideofi this body Ill is a straight sidey edge- I3, these edgesIl andy I3 effecting a true square in the use of the body. .The end'ofthe body IU opposite and remote from the notch I2 is ,formed 15 with acircular rim I4 providing a seat for. a turnable protractor ring I5', ithaving a thickened channeled-portion I6 offset with relation to the rimI4v and constituting aV guide and carrier portion for a ruling'blade I1which, as iscus- 20 tomary, carries-at 'opposite faces thereof scales ormeasuring graduations I8 for lineal measurements in the-use thereof. Theoiset portion has fitted therewith the usual knurled nut equipped clampor latchng member I9- for holding the blade IIy in its shifted positionas the-same is slidably fitted in this thickened portion I6, the bladeI1 at the end next to the body IU being rounded at 2D similarly to thecircular contour of the rim I4 so that when the said blade I1 has beenshifted in the thickened portion I6 to bring this end next to theprotractor ring I5 the said end 20 will match the rim I4 and thuseliminate prctrusion with respect thereto. The blade I1 when parallelwith the edge I3 of the 35 body I0 has its outermost edge flushtherewith and will constitute an extension of such edge especially whenthe instrument is used for spanning purposes and in leveling an objector objects in relation to each other.

The body I0 is of skeleton formation and built within the same are thespirit levels 2I and 22, respectively, these being disposed at rightangles to each other, the level 2| lies parallel with the edge I3 whilethe level 22 is parallel with 45 the edge II of said body so that theselevels are convenient in the placement of the body I0 for level readingwith respect to the edges II and I3. Either of. these levels 2| and 22are serviceable-for plumb reading in the placement of the body Ill withrespect to a piece of work. The edges II and I3 are the working edges ofthe body I0.

The protractor ring I5 is held within the rim I4 in the usual Well-knownmanner for rotation 55 therein and on its exposed face is provided aprotractor scale 23 cooperating with witness points 24 provided on therim I4, in this instance the points 24 being located diametricallyopposite each other for the reading of the degrees under the adjustmentof the protractor ring I5. In the periphery of the ring I5 are sockets25, these being engageable by a latching pin 26 it being thrown tolatching position by a spring 21 and at its outer end carries a fingergrip 28, the pin being suitably set within the rim I4 for the engagementthereof selectively in said sockets 25 in the ring I5. These sockets 25in the ring I5 are set with relation to the scale 23 so as to permit ofthe latc'hing4 of the blade I'I at a ninety degree angle Y,with ,respectto the perpendicular.

O11 the body l0 at the Side ODDOSii the Carsaidfsid'esofV the' mountingfor cooperation with riage of the protractor ring I5 is formeda circularrim 33 in which is tted a rotatable disk 34' and this disk hasperipherally thereof gear teeth 35 meshing with a companion pinion 36journaled upon'a stud screw 3l iitted in the body I0, the pinion 36being formed with a turning knob 38 and thus it will be seen from Figure5 of the drawing that by turning the knob 38 the' .pinion 35 willtransmit motion to the disk 34 forthe rotation thereof. Carried by thisdisk 34 is a squared mounting 39 forming a casing for a group of spiritlevels 40, these being set at right angles to each other and are exposedthrough reading openings 4I in said casing at the four sides of thesame. These spirit levels 40 are for cooperationwith the edges II and I3and the centering notch I2 of the instrument. Carried by the rim 33 arethe graduated scales 42 and 43, respectively. 'I'he scale 42 is a degreescale while the scale 43 is a percent scale and cooperating with 'thesescales 42 and 43 are the pointers or indicators 44 provided on the disk34 in the servicing of the instrument hereinafter fully described.

What'is claimed is:

' 1. An instrument of the character described comprising a frame havinga straight side and rounded at one end, a full circular protractor r0-tatably fitting the rounded end of said frame and having a rule bladeguide peripherally thereof, a rule blade slidable in said guide andhaving a rounded end for matching the rounded end of said frame whenregistering therewith, means tted in the guide for locking the blade inadjusted position, a circular rim on the frame at the side opposite theprotractor, a rotatable disk fitting the rim and having peripheral gearteeth, a stud screw on the frame next to the rim, a pinion journaled onthe screw andmeshing with the gear teeth on .the vdisk and having aturning knob projected laterally from the frame, a

squared mounting detacliably tting the outermost side of the said disk,and a group of spirit levels held by said mounting and disposed at rightangles to each other adjacent to the sides of saidu mounting andselectively visible at the the straight edge of the frame.

2. An instrument of the character described comprising afframe having yastraight side and rounded at one end, a full circularprotractor-rotatably fitting the rounded end of said frame and having a'ruleblade guideperipherally thereof, a rule blade slidable in said guideand havinga rounded end for matching the rounded-end of saidA frame whenregistering therewith: means fitted in the guide for locking thebladeiin adjusted position, a circular rim on the frame at the sideopposite the protractor, a rotatable disk fitting the rim andhaving'peripheral gear teeth, a stud screw on the frame next tothe rim,a pinion journaledon the screw andmeshing with the gear teeth on thedisk and having a turning knob projected laterally from the frame,afsquared mounting detachably fitting the outermost side of the saiddisk, a group of spirit levels held by said mounting and disposed vatright angles to each other adjacent to the sides of said mounting forcooperation with the straight edge of the frame, graduated scales onsaidrim and diametrically opposed to each other, and pointers on thedisk and coactive withtlie said scales, respectively. l l l LEM W.WOLFE.

